Hello this is my first time to post. I have an electromagnet powered by a car battery charger set at 12 volts the problem is I can't get the electromagnet to repel the neodymium magnet. I have tried switching around the positive and negative leads of the power supply and switching the side of the magnet that is facing the electromagnet. The electromagnet will pick up a wire strippers yet it wont repel a magnet. So I'm just wondering does anyone know what I'm doing wrong.